Memory loss linked to stress

Scientists have discovered how stress contributes to memory loss in old rats.

High levels of the stress hormone cortisol have previously been linked to forgetfulness in old age. Researchers looked at two receptors in the brain that react to cortisol. Low levels of cortisol were found to activate one receptor and help memory function in aged rats. But when cortisol levels became too high, the second receptor was also activated. This reduced memory function in the rats, making it harder for them to navigate a maze.

Using a new chemical, researchers were able to block cortisol production in cells. This improved the ability of the rats to navigate the maze.

Understanding the mechanisms in the brain which affect memory could lead to treatments for conditions such as Alzheimer's.